Lubricant base oil and method for producing same

Abstract

A lubricant base oil that is a hydrocarbon oil that satisfies any of the following conditions (i), (ii) and (iii): (i) a hydrocarbon oil having a kinematic viscosity at 100° C. of 3.0 to 5.0 mm 2 /s, a viscosity index of 145 or more, and an SBV viscosity at −20° C. of 3,000 to 60,000 mPa·s, (ii) a hydrocarbon oil having a kinematic viscosity at 100° C. of 5 to 9 mm 2 /s, a viscosity index of 155 or more, and an SBV viscosity at −20° C. of 3,000 to 30,000 mPa·s, and (iii) a hydrocarbon oil having a kinematic viscosity at 100° C. of 2.0 to 3.0 mm 2 /s, a viscosity index of 130 or more, and an SBV viscosity at −30° C. of 1,000 to 30,000 mPa·s.

1 . A lubricant base oil that is a hydrocarbon oil that satisfies any of the following conditions (i), (ii) and (iii):
 (i) a hydrocarbon oil having a kinematic viscosity at 100° C. of 3.0 to 5.0 mm 2 /s, a viscosity index of 145 or more, and an SBV viscosity at −20° C. of 3,000 to 60,000 mPa·s,   (ii) a hydrocarbon oil having a kinematic viscosity at 100° C. of 5 to 9 mm 2 /s, a viscosity index of 155 or more, and an SBV viscosity at −20° C. of 3,000 to 30,000 mPa·s, and   (iii) a hydrocarbon oil having a kinematic viscosity at 100° C. of 2.0 to 3.0 mm 2 /s, a viscosity index of 130 or more, and an SBV viscosity at −30° C. of 1,000 to 30,000 mPa·s.   
     
     
         2 . The lubricant base oil according to  claim 1 , wherein the hydrocarbon oil satisfies the condition (i) and has an SBV viscosity at −30° C. of 5,000 to 500,000 mPa·s. 
     
     
         3 . The lubricant base oil according to  claim 1 , wherein the hydrocarbon oil satisfies the condition (i) and has a freezing point of −20 to −5° C. 
     
     
         4 . The lubricant base oil according to  claim 1 , wherein the hydrocarbon oil satisfies the condition (i) and has a ratio of CH 2  carbons constituting a main chain to all carbons constituting the lubricant base oil of 15% or more in a  13 C-NMR analysis. 
     
     
         5 . The lubricant base oil according to  claim 1 , wherein the hydrocarbon oil satisfies the condition (i) and has a cycloparaffin content of 50% or less in an FD-MS analysis. 
     
     
         6 . The lubricant base oil according to  claim 1 , wherein the hydrocarbon oil satisfies the condition (ii) and has an SBV viscosity at −25° C. of 5,000 to 500,000 mPa·s. 
     
     
         7 . The lubricant base oil according to  claim 1 , wherein the hydrocarbon oil satisfies the condition (ii) and has a freezing point of −15 to −5° C. 
     
     
         8 . The lubricant base oil according to  claim 1 , wherein the hydrocarbon oil satisfies the condition (ii) and has a ratio of CH 2  carbons constituting a main chain to all carbons constituting the lubricant base oil of 20% or more in a  13 C-NMR analysis. 
     
     
         9 . The lubricant base oil according to  claim 1 , wherein the hydrocarbon oil satisfies the condition (ii) and has a cycloparaffin content of 60% or less in an FD-MS analysis. 
     
     
         10 . The lubricant base oil according to  claim 1 , wherein the hydrocarbon oil satisfies the condition (iii) and has an SBV viscosity at −35° C. of 3,000 to 500,000 mPa·s. 
     
     
         11 . The lubricant base oil according to  claim 1 , wherein the hydrocarbon oil satisfies the condition (iii) and has a freezing point of −30 to −10° C. 
     
     
         12 . The lubricant base oil according to  claim 1 , wherein the hydrocarbon oil satisfies the condition (iii) and has a ratio of CH 2  carbons constituting a main chain to all carbons constituting the lubricant base oil of 15% or more in a  13 C-NMR analysis. 
     
     
         13 . The lubricant base oil according to  claim 1 , wherein the hydrocarbon oil satisfies the condition (iii) and has a cycloparaffin content of 30% or less in an FD-MS analysis. 
     
     
         14 . A method for producing a lubricant base oil, the method comprising:
 a first step of fractionating, from a hydrocarbon oil containing a base oil fraction and a heavy fraction that is heavier than the base oil fraction, the base oil fraction and the heavy fraction;   a second step of returning a cracked oil obtained by hydrocracking the heavy fraction fractionated in the first step, to the first step;   a third step of obtaining a dewaxed oil by performing hydroisomerization dewaxing of the base oil fraction;   a fourth step of obtaining a refined oil by refining the dewaxed oil; and   a fifth step of obtaining a lubricant base oil that is a hydrocarbon oil that satisfies any of the following conditions (i), (ii) and (iii):   (i) a hydrocarbon oil having a kinematic viscosity at 100° C. of 3.0 to 5.0 mm 2 /s, a viscosity index of 145 or more, and an SBV viscosity at −20° C. of 3,000 to 60,000 mPa·s,   (ii) a hydrocarbon oil having a kinematic viscosity at 100° C. of 5 to 9 mm 2 /s, a viscosity index of 155 or more, and an SBV viscosity at −20° C. of 3,000 to 30,000 mPa·s, and   (iii) a hydrocarbon oil having a kinematic viscosity at 100° C. of 2.0 to 3.0 mm 2 /s, a viscosity index of 130 or more, and an SBV viscosity at −30° C. of 1,000 to 30,000 mPa·s, by fractionation of the refined oil.   
     
     
         15 . The method according to  claim 14 , wherein the lubricant base oil obtained in the fifth step satisfies the condition (i) and has a freezing point of −20 to −5° C. 
     
     
         16 . The method according to  claim 14 , wherein the lubricant base oil obtained in the fifth step satisfies the condition (ii) and has a freezing point of −15 to −5° C. 
     
     
         17 . The method according to  claim 14 , wherein the lubricant base oil obtained in the fifth step satisfies the condition (iii) and has a freezing point of −30 to −10° C. 
     
     
         18 . The method according to  claim 14 , wherein the third step is a step of performing hydroisomerization dewaxing of the base oil fraction in the presence of a hydroisomerization catalyst containing at least one crystalline solid acidic substance selected from the group consisting of ZSM-22-type zeolite, ZSM-23-type zeolite, SSZ-32-type zeolite, and ZSM-48-type zeolite and platinum and/or palladium as an active metal. 
     
     
         19 . The method according to  claim 14 , wherein the hydrocarbon oil is obtained by using GTL wax obtained by a Fischer-Tropsch synthesis or slack wax obtained by solvent dewaxing, as a raw material.